Avoid using os.path.normpath on Windows with files destined for Linux. (

#1621)

container/build_tar.py

@@ -21,6 +21,7 @@
 import json
 import os
 import os.path
+import posixpath
 import subprocess
 import sys
 import re
@@ -48,14 +49,16 @@ def parse_pkg_name(metadata, filename):
       return os.path.basename(os.path.splitext(filename)[0])
 
   def __init__(self, output, directory, compression, root_directory,
-               default_mtime, enable_mtime_preservation, xz_path):
+               default_mtime, enable_mtime_preservation, xz_path,
+               force_posixpath):
     self.directory = directory
     self.output = output
     self.compression = compression
     self.root_directory = root_directory
     self.default_mtime = default_mtime
     self.enable_mtime_preservation = enable_mtime_preservation
     self.xz_path = xz_path
+    self.force_posixpath = force_posixpath
 
   def __enter__(self):
     self.tarfile = archive.TarFileWriter(
@@ -92,7 +95,10 @@ def add_file(self, f, destfile, mode=None, ids=None, names=None):
       ids = (0, 0)
     if names is None:
       names = ('', '')
-    dest = os.path.normpath(dest)
+    if self.force_posixpath:
+        dest = posixpath.normpath(dest)
+    else:
+        dest = os.path.normpath(dest)
     self.tarfile.add_file(
         dest,
         file_content=f,
@@ -123,7 +129,10 @@ def add_empty_file(self, destfile, mode=None, ids=None, names=None,
       ids = (0, 0)
     if names is None:
       names = ('', '')
-    dest = os.path.normpath(dest)
+    if self.force_posixpath:
+        dest = posixpath.normpath(dest)
+    else:
+        dest = os.path.normpath(dest)
     self.tarfile.add_file(
         dest,
         content='' if kind == tarfile.REGTYPE else None,
@@ -187,7 +196,10 @@ def add_link(self, symlink, destination):
       symlink: the name of the symbolic link to add.
       destination: where the symbolic link point to.
     """
-    symlink = os.path.normpath(symlink)
+    if self.force_posixpath:
+        symlink = posixpath.normpath(symlink)
+    else:
+        symlink = os.path.normpath(symlink)
     self.tarfile.add_file(symlink, tarfile.SYMTYPE, link=destination)
 
   @contextmanager
@@ -337,7 +349,8 @@ def main(FLAGS):
   # Add objects to the tar file
   with TarFile(FLAGS.output, FLAGS.directory, FLAGS.compression,
                FLAGS.root_directory, FLAGS.mtime,
-               FLAGS.enable_mtime_preservation, FLAGS.xz_path) as output:
+               FLAGS.enable_mtime_preservation, FLAGS.xz_path,
+               FLAGS.force_posixpath) as output:
     def file_attributes(filename):
       if filename.startswith('/'):
         filename = filename[1:]
@@ -460,5 +473,9 @@ def validate_link(l):
   parser.add_argument('--xz_path', type=str,
     help='Specify the path to xz as a fallback when the Python '
     'lzma module is unavailable.')
+
+  parser.add_argument('--force_posixpath', type=bool, default=False,
+    help='Force the use of posixpath when normalizing file paths. This is useful' 
+    'when building in a non-posix environment.')
 
   main(parser.parse_args())

container/layer.bzl

@@ -129,6 +129,7 @@ def build_layer(
     elif build_layer_exec.path.endswith(".exe"):
         # Building on Windows, but not for Windows. Do not use the default root directory.
         args.add("--root_directory=")
+        args.add("--force_posixpath=true")
 
     all_files = [struct(src = f.path, dst = _magic_path(ctx, f, layer)) for f in files]
     all_files += [struct(src = f.path, dst = path) for (path, f) in file_map.items()]